<template>
    <div class='carousel' @mouseenter="stop" @mouseleave="start">
        <ul class="carousel-body">
            <li class="carousel-item" v-for="(item, i) in list" :key="item.id" :class="{ fade: i === curr }">
                <RouterLink v-if="item.hrefUrl" :to="item.hrefUrl">
                    <img v-lazy="item.imgUrl">
                </RouterLink>

                <div v-else class="slider">
                    <RouterLink v-for="goods in item" :key="goods.id" :to="`/product/${goods.id}`">
                        <img :src="goods.picture" alt="">
                        <p class="name ellipsis">{{ goods.name }}</p>
                        <p class="price">&yen;{{ goods.price }}</p>
                    </RouterLink>
                </div>
            </li>
        </ul>
        <a href="javascript:;" class="carousel-btn prev" @click="toggle(-1)"><i
                class="iconfont icon-angle-left"></i></a>
        <a href="javascript:;" class="carousel-btn next" @click="toggle(1)"><i
                class="iconfont icon-angle-right"></i></a>
        <div class="carousel-indicator">
            <span v-for="(item, i) in list" :key="item.id" @click="handleIndicator(i)"
                :class="{ active: i === curr }"></span>
        </div>
    </div>
</template>

<script>
export default {
    name: 'Carousel'
}
</script>
<script setup>
import { ref, watch, onUnmounted } from 'vue'
const props = defineProps({
    list: {
        type: Array,
        default: () => []
    },
    duration: {
        type: Number,
        default: 3000
    }
})

const curr = ref(0)
const toggle = (val) => {
    const newVal = curr.value + val
    if (newVal < 0) {
        curr.value = props.list.length - 1
        return
    } else if (newVal > props.list.length - 1) {
        curr.value = 0
        return
    }
    curr.value = newVal
}
const handleIndicator = (i) => {
    curr.value = i
}

// 自动轮播
let timer = ref(null)
const autoPlayFn = () => {
    stop()
    timer = setInterval(() => {
        curr.value++
        if (curr.value >= props.list.length)
            curr.value = 0
    }, props.duration)
}

const start = () => {
    stop()
    if (props.list.length)
        autoPlayFn()
}

const stop = () => {
    clearInterval(timer)
}

watch(() => props.list, (newVal) => {
    // 有数据&开启自动播放，才调用自动播放函数
    if (newVal && props.list.length)
        autoPlayFn()
}, { immediate: true })

// 组件消耗，清理定时器
onUnmounted(() => {
    clearInterval(timer)
})

</script>
<style scoped lang="scss">
.carousel {
    width: 100%;
    height: 100%;
    min-width: 300px;
    min-height: 150px;
    position: relative;

    &-body {
        width: 100%;
        height: 100%;
    }

    &-item {
        width: 100%;
        height: 100%;
        position: absolute;
        left: 0;
        top: 0;
        opacity: 0;
        transition: opacity 0.5s linear;

        &.fade {
            opacity: 1;
            z-index: 1;
        }

        img {
            width: 100%;
            height: 100%;
        }
    }

    &-indicator {
        position: absolute;
        left: 0;
        bottom: 20px;
        z-index: 2;
        width: 100%;
        text-align: center;

        span {
            display: inline-block;
            width: 12px;
            height: 12px;
            background: rgba(0, 0, 0, 0.2);
            border-radius: 50%;
            cursor: pointer;

            ~span {
                margin-left: 12px;
            }

            &.active {
                background: #fff;
            }
        }
    }

    &-btn {
        width: 44px;
        height: 44px;
        background: rgba(0, 0, 0, .2);
        color: #fff;
        border-radius: 50%;
        position: absolute;
        top: 228px;
        z-index: 2;
        text-align: center;
        line-height: 44px;
        opacity: 0;
        transition: all 0.5s;

        &.prev {
            left: 20px;
        }

        &.next {
            right: 20px;
        }
    }

    &:hover {
        .carousel-btn {
            opacity: 1;
        }
    }

    // 轮播商品
    .slider {
        display: flex;
        justify-content: space-around;
        padding: 0 40px;

        >a {
            width: 240px;
            text-align: center;

            img {
                padding: 20px;
                width: 230px !important;
                height: 230px !important;
            }

            .name {
                font-size: 16px;
                color: #666;
                padding: 0 40px;
            }

            .price {
                font-size: 16px;
                color: $priceColor;
                margin-top: 15px;
            }
        }
    }
}
</style>